This invention generally relates to a ventilated seat for a vehicle. More specifically, this invention relates to a seat pad assembly of an air distribution system for a motor vehicle ventilated seat.
One of the recent features associated with vehicle design is the ventilated seat. Ventilated seats in the past have used distribution devices and pad assemblies within the seat assembly to either push air into or draw air from the occupant area of the ventilated seat. The air distribution devices of current techniques in the art often use a plenum type distribution device in seat pad assemblies. The plenum can be formed as a channel in a high-density plastic foam seat cushion. For a bottom or seating cushion of the seat, the plenum could be an open-topped, horseshoe-shaped channel in the upper surface of the cushion. Respective open ends of the horseshoe-shaped channel would be sized and positioned to extend under the thighs of the seat occupant. The open top of the channel, and perhaps the entire surface of the cushion, might be covered with a highly porous but strong fabric that is bonded to the upper surface of the cushion, particularly at the edges of the channel. This fabric supports other layers that are applied over the top of the channel. The entire upper surface of the cushion is covered with highly porous plastic foam, such as open-celled foam, which is also referred to herein as reticulated foam. A decorative trim cover is bonded and/or sewn to the outer surface of the open celled foam. The trim cover might be a layer of a decorative porous fabric, or a decorative layer of some other material that is highly perforated at least over the plenum area. The trim layer and the porous foam layer allow air to flow readily into or out of the cushion channel. Providing means, such as a fan, to draw air from, or blow air into the cushion channel ventilates the seat.
Density of the foam for such a seat cushion has to be a high enough to prevent collapse of its air channels when the seat is occupied. This can entail a compromise in the seat comfort and style, and can unduly limit the amount and quality of comfort and style features that may be incorporated into the trim cover of the ventilated seat. The type of pad assembly described above can eventually show wear lines on the trim cover and read-through of the channels through the trim cover. In addition, the assembly of the various layers is labor intensive. Moreover, meticulous care in assembly, quality control and inspection is required to insure that such wear lines and read-through do not occur prematurely. In this invention, such wear lines and channel read-through in the trim can be at least significantly reduced, if not avoided entirely. In addition, the assembly process of the ventilated seat pad can be made less critical, and variations in quality avoided, which reduces overall cost of manufacture. Accordingly, the manufacturing process becomes more efficient, and problems with the look and feel of ventilated seats are reduced.
Accordingly, this invention provides for a ventilated seat that overcomes the problems and disadvantages of the prior techniques in the art. The invention also provides for an improved pad assembly for a ventilated seat. The pad assembly allows use of a non-rigid air distribution device, while substantially resisting pinching or reduction of the cross-sectional area of the air plenum in the seat pad cushion. Importantly, the invention reduces the development of wear lines and read-through on the trim layer. The invention also provides an improved assembly technique that reduces manufacturing cost and improves uniformity in the manufactured product, while still allowing use of a non-rigid plenum for air distribution.
Briefly, the invention involves a pad assembly for a ventilated seat. The pad assembly includes a cushion member having an insert member of higher density foam providing an air distribution plenum. A channel whose open top is closed by a high density foam cover forms the plenum in the higher density insert member. The covering member is preferably molded as an integral part of the insert member. A trim layer would ordinarily cover the cushion, including the insert and insert channel cover. An open-celled foam layer could be used between the decorative trim layer and the cushion, including the insert and insert channel cover, to facilitate lateral air distribution to or from the cushion plenum while the seat is occupied.
The high density foam covering member on the insert channel can include conformations on its inner, i.e., lower, surface to nest with the insert channel and/or to reinforce the covering member in the channel area. Conformations can be used on the outer, i.e., upper, surface and/or on the edges of the covering member for decorative, structural, and/or seating comfort purposes, and to obscure read through and/or wear lines in the trim at edges of the channel. The channel-covering member can be used to cover some or all of the cushion upper surface, depending on the fashion needs of the trim covering. The covering member has perforations over the insert channel to facilitate airflow through the covering member into or out of the overlying porous trim layer. Surface grooves and the like in the channel covering member can be used adjacent the perforations to facilitate lateral airflow to or from the perforations.
The cushion plenum is connected to means for supplying or removing air, which can be an outlet of the vehicle air conditioning system, or the outlet of a separate impeller, such as a fan under the seat. In the prior art, a separate soft but substantially air impermeable member is used as a connector between the seat cushion plenum and the fan or air conditioning outlet. In a preferred example of this invention, the connector member can take a new form. The connector member can be integrally molded in the higher density foam, as a unique flat shape, along with the insert member. The cushion insert would include a port from the insert channel with an external port collar, around which the connector member would be wrapped. The connector member would extend down through a hole in the seat cushion, to provide a good airflow tube for connection with the air flow means. Thus, the assembly can be done with fewer critical steps and fewer separate parts. Appearance and durability are maximized, and cost is reduced.